Heat pump evaporator tubes are enhanced tubes specifically designed for air-to-water heat pump evaporators. Unlike standard air conditioning evaporators, air source heat pump evaporators operate under low ambient temperature conditions, with evaporation temperatures as low as -15°C to -25°C. This requires excellent low-temperature heat transfer performance and freeze resistance of the tubes.

Kaiyuan's heat pump evaporator tubes feature optimized internal groove parameters, maintaining a high heat transfer coefficient even at low evaporation temperatures and low refrigerant mass flux. The wall thickness is carefully designed with an increased safety margin to resist cracking caused by freezing. These tubes are compatible with various heat pump refrigerants, including R134a, R410A, R32, and R290.

Core Advantages

Optimized for low-temperature operation

The special grooved profile design maintains efficient heat transfer within an evaporation temperature range of -10°C to -25°C, ensuring reliable heating capacity in cold climates.

Anti-freeze design

The redundant wall thickness combined with high-ductility copper material reduces the risk of tube rupture caused by icing during defrost cycles or extreme operating conditions.

Compatible with environmentally friendly refrigerants

The grooved profile is optimized for mildly flammable (R32) and flammable (R290) refrigerants, balancing heat transfer efficiency with safety considerations for reduced charge systems.

Defrost cycle stability

The groove geometry facilitates condensate drainage during defrost cycles, minimizes frost residue, and ensures consistent heating performance in subsequent operating cycles.

Technical Parameters

Outer Diameter (mm)	Bottom Wall (mm)	Tooth Height (mm)	Number of Teeth	Helix Angle (°)	Weight (g/m)	Heat Transfer Area (m²/m)	Material
7.00	0.25-0.32	0.12-0.18	45-55	15-25	42-50	0.021-0.024	TP2, T2
9.52	0.30-0.40	0.14-0.20	50-65	18-28	52-62	0.025-0.028	TP2, T2
7.94	0.27–0.35	0.12–0.18	45-60	18>28	63–75	0.028–0.032	TP2, T2

Typical Applications

Residential Air-to-Water Heat Pump Evaporator

Home heat pump water heaters and space heating systems need to operate reliably in cold climates.

Commercial Heat Pump Water Heater

Large-capacity heat pump water heaters for hotel, school, hospital, and commercial hot water applications.

Air Source Heat Pump Heating System

Evaporator for air-to-water heat pump heating systems in residential and light commercial buildings.

Heat Pump Dryer Evaporator

Evaporator for heat pump dryers and industrial heat pump drying systems.

Frequently Asked Questions

Q: Can the heat pump evaporator tube be directly replaced with a standard AC inner groove tube?

We do not recommend direct replacement. Heat pump evaporator tubes are specifically designed for low evaporation temperature conditions (-10°C to -25°C), featuring optimized groove geometry and thicker anti-freeze walls. Standard AC inner groove tubes are optimized for higher evaporation temperatures (typically 5°C to 10°C). When used in heat pump applications, especially in cold climates, they may reduce efficiency and increase the risk of freezing.

Q: What special requirements does the R32 heat pump system have for evaporator tubes?

R32 operates at higher pressures than R410A, and as a mildly flammable (A2L) refrigerant, safety considerations are paramount. For R32 heat pump systems, we recommend our specially optimized groove profiles to balance heat transfer performance and reduce refrigerant charge. The tubes are manufactured with enhanced wall thickness consistency to withstand higher operating pressures. Additionally, the groove geometry is fine-tuned according to the thermophysical properties of R32 to maximize efficiency under low ambient temperatures.

Q: How to prevent tube freeze damage in low-temperature environments?

Our anti-freeze strategy combines three methods: (1) Increased wall thickness with a safety margin higher than standard AC tubes to withstand ice expansion pressure; (2) High-toughness TP2 copper material with excellent low-temperature ductility, adapting to slight deformation without cracking; (3) Groove geometry that promotes complete drainage during defrost cycles to minimize water retention. For extreme cold climate applications, we also offer enhanced wall thickness options upon request.

Q: Do you provide complete finned heat pump evaporator assemblies?

Currently, we specialize in producing copper tube components for heat pump evaporators, rather than complete finned evaporator assemblies. However, we can cooperate with authorized fin stamping partners to provide matched tube and fin combinations. If you require a complete evaporator coil assembly, please contact our sales team with your specifications, and we will connect you with suitable OEM partners who can manufacture complete assemblies using our tubes.

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